Your explaination makes the most sense to me. Music where you want it. My friend's house of double cat5, double rg6, etc in every room sounds way over board.
From teknobeam1 and katahdin's posts, it sound like were still aways away from lots of solutions for distributed component video. With no mention of DVI or HMDI (?) distribution.
If I were building a house, I think I'd stick conduit to every room. That way you can future proof, if there is such a beast, your infrastructure. I'd also wire up the rooms for audio. At least the ones I really cared about. I'm not sure I need audio in the powder rooms. Of course, one super bowl party can change that thought.
For my current home, distributed audio to the dining room and the deck is enough for the moment. I'm sure the kids will not want to listen to the same music as mom and dad. Separate components in the family room and future HT in the basement should fit the bill. Shuffling the old stuff to the garage will answer that call. No the kids will not get video in their rooms. My son would watch it 24 X 7. Wireless networking for the PC should handle that end.